A fire at an electricity substation Thursday left 63,000 people without power in the centre and southeast of the Spanish capital Madrid. The blackout plunged transport into chaos as traffic lights stopped functioning. Passengers of an underground train had to be evacuated after it stopped in a tunnel, radio reports said. The fire temporarily affected 12 underground lines, but service was soon restored. Two people who had been at the substation of the electricity company Union Fenosa, the site of the fire, were treated for shock. Several houses in the area were evacuated as a preventative measure. Firefighters were fighting the blaze, thought to have originated in a transformer. Officials said electricity would be restored as soon as possible. The stoppage also affected another electricity station, leaving 15,000 more people in the Salamanca neighbourhood without power for a short period.